Fabrication routes for advanced first wall design alternatives
| Autor: | Jan Hoffmann, N. De Wispelaere, Gerald Pintsuk, Michael Rieth, Y. de Carlan, J. Henry, Michael Dürrschnabel, Steffen Antusch, Christian Zeile, Jörg Rey, Bradut-Eugen Ghidersa, Heiko Neuberger, Giacomo Aiello, Simon Bonk, E. Simondon |
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| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
Nuclear and High Energy Physics
Heat-affected zone Fabrication Materials science 020209 energy Nuclear engineering dissimilar joints chemistry.chemical_element materials technology 02 engineering and technology 7. Clean energy 01 natural sciences 010305 fluids & plasmas Operating temperature high heat flux test 11. Sustainability 0103 physical sciences oxide dispersion strengthened (ODS) steel 0202 electrical engineering electronic engineering information engineering Embrittlement Engineering & allied operations Helium helium cooling loop Condensed Matter Physics Microstructure diffusion bonding chemistry Heat flux Creep blanket first wall ddc:620 |
| Zdroj: | Nuclear fusion 61(11), 116067-(2021). doi:10.1088/1741-4326/ac2523 Nuclear fusion, 61 (11), 116067 |
| ISSN: | 0029-5515 1741-4326 |
| DOI: | 10.5445/ir/1000139279 |
| Popis: | In future nuclear fusion reactors, plasma facing components have to sustain specific neutron damage. While the majority of irradiation data provides a relatively clear picture of the displacement damage, the effect of helium transmutation is not yet explored in detail. Nevertheless, available results from simulation experiments indicate that 9%-chromium steels will reach their operating limit as soon as the growing helium bubbles extent a critical size. At that point, the material would most probably fail due to grain boundary embrittlement. In this contribution, we present a strategy for the mitigation of the before-mentioned problem using the following facts. (1) The neutron dose and related transmutation rate decreases quickly inside the first wall of the breeding blankets, that is, only a plasma-near area is extremely loaded. (2) Nanostructured oxide dispersion strengthened (ODS) steels may have an enormous trapping effect on helium, which would suppress the formation of large helium bubbles for a much longer period. (3) Compared to conventional steels, ODS steels also provide improved irradiation tensile ductility and creep strength. Therefore, a design, based on the fabrication of the plasma facing and highly neutron and heat loaded parts of blankets by an ODS steel, while using EUROFER97 for everything else, would extend the operating time and enable a higher heat flux. Consequently, we (i) developed and produced 14%Cr ferritic ODS steel plates and (ii) optimized and demonstrated a scalable industrial production route. (iii) We fabricated a mock-up with five cooling channels and a plated first wall of ODS steel, using the same production processes as for a real component. (iv) Finally, we performed high heat flux tests in the Helium Loop Karlsruhe, applying a few hundred short and a few 2 h long pulses, in which the operating temperature limit for EUROFER97 (i.e. 550 ◦C) was finally exceeded by 100 K. (v) Thereafter, microstructure and defect analyses did not reveal critical defects or recognizable damage. Only a heat affected zone in the EUROFER/ODS steel interface could be detected. However, a solution to prohibit the formation of such heat affected zones is given. These research contributions demonstrate that the use of ODS steel is not only feasible and affordable but could make a decisive difference in the future design and performance of breeding blankets. |
| Databáze: | OpenAIRE |
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